1. Field of the Invention
The present invention relates to a client server system.
2. Description of the Related Art
Recently, a system that sends and provides image information (contents information) from a server device to a client terminal device them through a network is utilized. To the server device, a plurality of types of image apparatuses such as a television device, a video recorder, a personal video recorder (PVR), a tuner for broadcasting satellite (BS) and communication satellite (CS), a set top box (STB), a digital versatile disk (DVD) player, and the like, are connected for example. The server device is capable to send image information corresponding to the image apparatus connected to the server device, to the client terminal device.
In case resolution of the image information sent from the server device is different from a screen resolution of a display device connected to the client terminal device, the resolution of the image information is adjusted to the screen resolution of the display device by a scaling function of the display device. However, method relying on the scaling function of the display device has a problem. For example, size of an image displayed on the display device becomes smaller than the screen size of the display device once, and then becomes aligned to the screen size of the display device, thus a person observing the display device have an uncomfortable feeling.
In particular, for example, in case the resolution of the image information changes while sending the image information, in other words, in case an image information sending rate decreases even though the server device has sent to the client terminal device an image information with high definition (HD) image information, or in case sending an image information of standard definition (SD) image information becomes necessary due to an increase in number of client terminal device to which the image information is sent, the size of an image displayed in the display device becomes unmatched with the screen size of the display device in mid-course, thus causing a person observing the display device have an uncomfortable feeling.
Therefore, without relying on the scaling function of the display device, a method to adjust the resolution of the image information sent from the server device to the screen resolution of the display device at the client terminal device, before the image information is imputed to the display device, is disclosed in Japanese Laid-open Patent Specification No. 10-326169 and Japanese Laid-open Patent Specification No. 10-171730 (hereinafter referred to as patent documents 1 and 2 respectively).
However, in the aforementioned patent documents 1 and 2, the resolution of the image information sent from the server device is uniform regardless to the screen resolution of the display device connected to the client terminal device. That is, the server device sends SD image information even to the client terminal device connected with a display device with screen resolution of HD, for example. Therefore, a problem arises in that even though the client terminal device displays on the display device with screen resolution of HD, the SD image information converted into HD image information, image quality is degraded compared to a case when HD image information sent from the server device is displayed as it is. In order to solve this problem, a method in which the server device selects the resolution of the image information that is to be sent according to the screen resolution of the display device, can be mentioned. However, in such method, the server device needs to have a structure that can send HD image information and SD image information individually in accordance with the screen resolution of each display device, and results in high cost.
In addition, in the aforementioned patent documents 1 and 2, the client terminal device always checks the resolution of the image information sent from the server device. Therefore, the check is conducted even when image information having the same resolution as the screen resolution of the display device, and the image information can be displayed directly in the display device. Thus, it is not efficient.